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U3Gate

class qiskit.circuit.library.U3Gate(theta, phi, lam, label=None)

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Bases: Gate

Generic single-qubit rotation gate with 3 Euler angles.

Warning

This gate is deprecated. Instead, the following replacements should be used

U3(θ,ϕ,λ)=U(θ,ϕ,λ)U3(\theta, \phi, \lambda) = U(\theta, \phi, \lambda)
circuit = QuantumCircuit(1)
circuit.u(theta, phi, lambda)

Circuit symbol:

     ┌───────────┐
q_0:U3(ϴ,φ,λ)
     └───────────┘

Matrix Representation:

U3(θ,ϕ,λ)=(cos(θ2)eiλsin(θ2)eiϕsin(θ2)ei(ϕ+λ)cos(θ2))\providecommand{\th}{\frac{\theta}{2}}\\\begin{split}U3(\theta, \phi, \lambda) = \begin{pmatrix} \cos\left(\th\right) & -e^{i\lambda}\sin\left(\th\right) \\ e^{i\phi}\sin\left(\th\right) & e^{i(\phi+\lambda)}\cos\left(\th\right) \end{pmatrix}\end{split}
Note

The matrix representation shown here differs from the OpenQASM 2.0 specification by a global phase of ei(ϕ+λ)/2e^{i(\phi+\lambda)/2}.

Examples:

U3(θ,ϕ,λ)=eiπ+θ2P(ϕ+π)XP(θ+π)XP(λ)U3(\theta, \phi, \lambda) = e^{-i \frac{\pi + \theta}{2}} P(\phi + \pi) \sqrt{X} P(\theta + \pi) \sqrt{X} P(\lambda)U3(θ,π2,π2)=RX(θ)U3\left(\theta, -\frac{\pi}{2}, \frac{\pi}{2}\right) = RX(\theta)U3(θ,0,0)=RY(θ)U3(\theta, 0, 0) = RY(\theta)

Create new U3 gate.


Attributes

condition_bits

Get Clbits in condition.

decompositions

Get the decompositions of the instruction from the SessionEquivalenceLibrary.

definition

Return definition in terms of other basic gates.

duration

Get the duration.

label

Return instruction label

name

Return the name.

num_clbits

Return the number of clbits.

num_qubits

Return the number of qubits.

params

return instruction params.

unit

Get the time unit of duration.


Methods

control

control(num_ctrl_qubits=1, label=None, ctrl_state=None)

Return a (multi-)controlled-U3 gate.

Parameters

  • num_ctrl_qubits (int) – number of control qubits.
  • label (str or None) – An optional label for the gate [Default: None]
  • ctrl_state (int orstr or None) – control state expressed as integer, string (e.g. ‘110’), or None. If None, use all 1s.

Returns

controlled version of this gate.

Return type

ControlledGate

inverse

inverse()

Return inverted U3 gate.

U3(θ,ϕ,λ)=U3(θ,λ,ϕ)U3(\theta,\phi,\lambda)^{\dagger} =U3(-\theta,-\lambda,-\phi))

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